Uterine cancer is the fourth most common malignancy diagnosed in women in the United States (estimated 42,793 cases in 2009) and is the seventh most common cause of cancer death among U.S. women. Over 95% of all uterine cancers are cancers of the endometrium (lining of the body of the uterus). Lifetime probability of developing cancer of the uterus is 1 in 40 (U.S.). 35-50% of women ages 35-70 present with one or more risk factors for endometrial cancer.
Two different clinicopathologic subtypes are recognized based on light microscopic appearance, clinical behavior, and epidemiology: the estrogen-related (type I, endometrioid) and the non-estrogen-related types (type II, nonendometrioid such as papillary serous and clear cell). Despite it aggressiveness, endometrial cancer is difficult to diagnose, thus many patients present with symptoms of the late-stage cancer.